Novel microtiter plate format for testing germ tube formation and proposalof a cost-effective scheme for yeast identification in a clinical laboratory

The germ tube test is most widely used for presumptive identification of Ca ndida albicans. Conventional testing is relatively time-consuming due to th e hands-on time involved in preparing and viewing each isolate. In order to reduce work-load and costs we have developed a novel microtiter plate test format that offers several advantages: (i) use of removable strips of micr otiter wells placed in lockwell frames, (ii) only one pipetting step for ea ch isolate, (iii) direct micromorphological evaluation using an inverse mic roscope, (iv) use of a novel synthetic germ tube test medium, (v) reduction of the inoculum, permitting testing of minute colonies, (vi) thus, testing of different colonies in potentially mixed primary cultures of clinical sp ecimens is encouraged and facilitated. Implementing this microtiter based g erm tube test with simultaneous trehalase test for presumptive identificati on of Torulopsis (Candida) glabrata, we propose an identification scheme in cluding this test format. This has been implemented in our routine laborato ry permitting cost-effective presumptive identification of almost all clini cally relevant yeast species. (C) 1999 Elsevier Science Inc.